Combined support and chambering guide for magazine-fed



March 10, 1964 D; KATZ 3,123,927 COMBINED SUPPORT AND CHAMBERING GUIDEFOR MAGAZINE-FED CARTRIDGES WITH FRAGILE PROJECTILES Filed Dec. 27, 19622 Sheets-Sheet l Fig-.1-

INVENTOR. llnvicE L. K112 March 10,1964 D. L. KATZ 3,123,927

COMBINED SUPPORT AND CHAMBERING GUIDE FOR MAGAZINE-FED CARTRIDGES WITHFRAGILE PROJECTILES Filed Dec. 27, 1962 2 Sheets-Sheet 2 INVENTOR :U'uvi d L- Ku nz BY .iQi qo a r I Q-JQ-w WJI United States Patent "ice WW?3,123,927 COMBINED SUPPORT AND (If 2 a t GUHDE FQR MAGAZiNE-FED(ZARTRIDGES W i T H FRAGHLE PRQEECTIILES David L. Katz, Longmeadow,Mass, assignor to the United States of America as represented by theSecretary of the Army Filed Dec. 27, 1%2, Ser. No. 247,769 Claims. (Cl.42-18) (Granted under Title 35, U.S. Code (1952), see. 266) Theinvention described herein may be manufactured and used by or for theGovernment for governmental purposes without the payment of any royaltythereon.

This invention relates to firearms in which the cartridges arevertically fed from a magazine mounted in the top of the receiver and ismore particularly directed to means for arresting the feeding movementof each cartridge into position to be chambered by the forward movementof a longitudinally reciprocal bolt.

Small arms weapons which utilize longitudinally reciprocal bolts aregenerally fed from the open end of a magazine having opposed lips forretaining one or more rows of cartridges against the bias of a followerspring. During the forward movement of the bolt into battery position,contact thereof with the base of the cartridge then in engagement withthe retaining lips in the magazine lips such cartridge therefrom forentry into the breech end of the barrel. Suitable cams in the receiverand in the breech end of the barrel serve to properly align and guidethe cartridge during the chambering movement thereof.

Although this method of transferring cartridges from a magazine to afully chambered position in the barrel subjects the cartridges torelatively severe impacts by the bolt and the camming surfaces in thebarrel and receiver, modern ammunition is usually designed to enduresuch rough handling without physical damage or premature ignitionthereof. However, such is not the case in every instance of militarycartridge design since one recent development has replaced the customaryrigid projectile nose by a relatively fragile structure which cannot bestripped from the magazine lips or cammed into the firing chamber in thebarrel without inviting the possibility of premature discharge.

Accordingly, in the development of a firearm capable of firing this typeof ammunition, it was found that the required handling safety could bestbe achieved by a lipless magazine vertically mounted in the top of thereceiver so that each cartridge falls or is spring-biased downwardlyinto the path of movement of the bolt. However, it was also discoveredthat this cartridge feeding method required a relatively complexarrangement of parts or fairly costly machining of the receiver in orderto halt the downward movement of the cartridges in proper alignment withthe firing chamber of the barrel.

It is, therefore, a primary object of this invention to provide arelatively simple and inexpensive means for halting the downward feedingmovement of cartridges from a lipless magazine vertically mounted in thetop of the receiver and at the same time positioning each cartridge incoaxial alignment with the firing chamber in the barrel.

A further object of this invention is to provide a cartridge supportingdevice of this type which can be readily coordinated with the movementsof a longitudinally reciprocal bolt without interference with the normalcartridge extracting and ejecting functions thereof.

Still another object of the present invention is to pro- Vide acartridge supporting device of the aforesaid type for a firearm in whichthe magazine is located in vertical alignment with the path along whichthe first cases are ejected.

Patented Mar. 1G, 19b4- The specific nature of the invention as Well asother objects and advantages thereof will clearly appear from adescription of a preferred embodiment as shown in the accompanyingdrawings in which:

FIG. 1 is a fragmentary longitudinal sectional view of the firearmshowing the bolt in battery position and partially sectioned to show thecartridge holding tray in the retracted position thereof;

' FIG. 2 is a similar view showing the bolt approaching the end ofrecoil movement and a fired cartridge case about to be ejected from thefirearm.

FIG. 3 is a similar view showing the bolt at the conclusion of recoilmovement with the cartridge holding tray released by the extractor forforward movement to the extended position thereof and the ejected caseabout to be replaced by the next cartridge in the magazine;

FIG. 4 is a similar view showing a cartridge being chambered by theforward movement of the bolt;

FIG. 5 is a perspective view of the extractor; and

FIG. 6 is an exploded view in perspective of the cartridge holding trayand the parts associated therewith.

This invention is designed for a firearm in which a lipless box magazineis vertically mounted in the top of the receiver to release eachcartridge therein into the forward path of a longitudinally reciprocalbolt. Longitudinal alignment of the cartridge with the firing chamber inthe barrel and the subsequent guidance thereof for proper entry thereinis effected by a tray slidably mounted to the underside of the bolt inposition to be biased forwardly into the vertical path of the cartridgebeing fed from the magazine as the bolt begins to counterrecoil. Duringthe chambering of this cartridge, the tray is forced rearwardly beneaththe bolt by contact with the breech end of the barrel and is latched inthis retracted position by engagement with the rear end of a cartridgeextractor pivotally mounted in the forward end of the bolt. During therecoil movement imparted to the bolt by the firing of the chamberedcartridge, the ejection of the fired case pivots the extractor out oflatching engagement with the cartridge holding tray which is then biasedforwardly to receive and support the next cartridge released from themagazine.

As shown in the drawings, the firearm in which the present invention isutilized is adapted to fire relatively large caliber cartridges 12 inwhich the projectile 14 is relatively fragile and is releasably crimpedin a cylindrical case 13 provided with the customary rim 15 andextractor groove 17. In order to avoid the possibility of physicalinjury or premature discharge which could result from the rough handlingnormally encountered in the feeding and chambering of conventionalammunition, the firearm is provided with a receiver 16 in which thecartridge feeding opening 18 therein is formed in the top thereof and isbracketed by vertical supports 2% between which a rectangular box typeof magazine 22 is releasably latched by any suitable means (not shown).In order to retain cartridges 12 in a vertical stack, the

' interior of magazine 22 is dimensioned to position the opposite endwalls thereof in respective slidable engagement with the base and noseof each cartridge therein. However, in the event such engagement isinsufiicient to prevent undesirable tilting of cartridges 12 in magazine22, one or both of the interior sidewalls thereof may include a verticalrib 24 adjacent the rear endwall for engagement with extractor groove 17in each of the stacked cartridges 12.

Since the retaining lips normally utilized in magazines of this type arehere completely eliminated, cartridges 12 are held therein by thecontact between the lowermost cartridge and the upper surface of a bolt28 slidably mounted in receiver 16 in longitudinal alignment with thefiring chamber 29 in the breech end of a barrel 3%) fixedly 3,1 ft Q3secured to the front end of receiver 16 immediately forward of cartridgefeeding opening 13 therein. While the slidable engagement of bolt 28 inreceiver 16 may be achieved in any one of several different ways, bolt28-is preferably provided with longitudinal ribs 32 on opposite sidesthereof adapted to engage in corresponding grooves 34 in receiver 16. Anoperating spring 36 is seated in receiver 16 to bias bolt 28 forwardlyand thereby advance any cartridge 12 in the path thereof into the firingchamber 29 in barrel 30.

Withdrawal of each fired cartridge case 13 from firing chamber 29 isaccomplished by an extractor38 pivotally mounted at 39 in a suitablerectangular recess 46 formed in the underside of bolt 28. As best shownat 41 in FIG. 5, the forward end of extractor 38 is reduced in width andterminates in a claw 42 adapted to project beyond the front face of bolt28 for entry into a slot 43 extending forwardly into the breech face ofbarrel 30 upon the completion of the counterrecoil movement of bolt 23as Will be hereinafter explained. The rear end of extractor 3% is ofincreased width, as indicated at 44, and is provided with a circularrecess 46 in the top thereof for seating one end of a coil spring 48.The opposite end of spring 43 is similarly seated in a correspondingrecess 50 extending upwardly into the underside of bolt 28 in. verticalalignment with extractor recess 46. Thus, spring 48 normally'urgesextractor claw 42 into position to engage rim 15 on cartridge case 13.

Upon the completion of extraction, the fired case 13 is adapted to beejected through a suitable opening 52 in the bottom of receiver 16 invertical alignment with cartridge feed opening 18 therein. This isaccomplished by the impact between the rear end of cartridge case 13 anda fixed ejector 54 depending from the upper wall of receiver 16 at apoint rearwardly of cartridge feed opening 18 therein. Bolt 28 issuitably channeled along the top thereof, as shown at 56, to permit therequired reciprocal movement thereof without interference by ejector 54.

During the pivotal movement of the fired cartridge case 13 about the tipof extractor claw 42, the lowermost cartridge 12 in magazine 22 is freedfor vertical movement into the counterrecoil path of bolt 28 in responseto the force of gravity or through the bias of a conventional followerspring (not shown) in the event a more rapid release is required. Inorder to halt this downward movement of the lowermost cartridge 12 inlongitudinal alignment with firing chamber 29 in barrel 30, a tray 58 issildably mounted to the underside of bolt 28 for movement between aforward extended position and a rearward retracted position. Tray 58 isformed with the same arcuate configuration as cartridge 12 and isprovided with inwardly turned ribs 60 adapted to slidably engage incorresponding grooves 62 formed in opposite sides of bolt 28.

The forward movement of tray 58 is achieved by a spring 64 mounted on anelongated rod 66 which is, in turn, supported by a post 68 projectingupwardly from the floor of tray 58 centrally between ribs 60 thereon.The front end of spring 64 is seated against the rear face of post 63while the rear end of spring 64 is retained by an enlarged head '7 onthe rear end of rod 66. The forward end of tray 58 is centrally slotted,as shown at '72, to a slightly greater width than the enlarged rear end44 of extractor 38. Slot 72 is continued rearwardly along tray 58 butwith a narrower width, as shown at 74,to form shoulders '76 forengagement with the rear end of extractor 38 as will be hereinafterexplained.

In order to mount tray 58 in close proximity to bolt 28, the latter isslotted along the underside thereof, as shown at 73, to provide apassageway for post 68. The forward end of bolt slot 78 communicateswith extractor recess 49 while the rear end of slot 78 is cylindricallyenlarged. as shown at St), to admit the enlarged head 79 at the rear endof rod 66. In order to lock rod 66 against longitudinal movement in bolt28, head 70 is provided with a projecting lug 82 adapted to engage in acorresponding track (not shown) formed into the periphery of cylindricalenlargement 80. Such engagement is achieved by a quarter turn or less ofrod 66 and a screwdriver slot 84 is provided in the rear end thereof forthat purpose.

The chambered cartridge 12 is fired by conventional means (not shown)whereupon the empty case 13 is withdrawn from barrel 30 by extractor 33during the subsequent recoil movement of bolt 28. Upon completion ofsuch withdrawal, case 13 strikes ejector 54 with a relatively sharpimpact and, as best shown in FIG. 3, is pivoted thereby about the fronttip of extractor claw 42 as a fulcrum for exit from the firearm throughejection opening 52. The impact between the fired case 13 and ejector 54also pivotsextractor 38 to raise the rear end 44 thereof out ofengagement with shoulders 76 of tray 53 which is thereby released forforward movement relative to bolt 28. Thereupon, tray 58 is forcedforwardly by spring 64 into the extended position thereof beneath thecartridge 12 then being expelled from magazine 22.

When fully extended, the length of tray 58 is such that the forward endthereof lies beyond the center of gravity of cartridge 12 to preventtipping thereof. Thus, inasmuch as the floor of tray 58 is substantiallyin vertical alignment with the bottom interior surface of firing chamber29, projectile 14 is supported in substantial coaxial alignmenttherewith. Although cartridge case rim 15 is of slightly larger diameterthan the body of cartridge 12, the resulting inclination thereof on tray58 will not cause any significant impact between projectile 14 and theWall surfaces in the interior of firing chamber 29.

Springs 36 and 64 are specifically designed so that cartridge 12 willland on the floor of tray 58 in position to be contacted by a camsurface 86 on the front end of extractor claw 42. Thus, since the biasof extractor spring 48 is insufficient to withstand the forward momentumof bolt 28 against the resistance provided by the weight of cartridge 12plus the frictional engagement thereof with the lowermost cartridge inmagazine 22, extractor claw 42 will ride over cartridge case rim 15 intoalignment with extractor groove 17 of cartridge 12 as shown in FIG. 4.

As bolt 28 continues to counterrecoil, the front end of tray 58 willcontact the breech face of barrel 30 and be forced rearwardly againstthe bias of spring 64. As soon as shoulders 76 in slot 72 of tray 58 aremoved rearwardly of extractor rear end 44, extractor 38 will be pivotedto complete the required engagement of claw 42 in extractor groove 17 ofcartridge 12. Thus, as the counterrecoil of bolt 28 is concluded,extractor claw 42 will enter into slot 43 in barrel 30 in position towithdraw the chambered cartridge 12 upon the firing thereof by suitablemeans (not shown).

Thus, there is here provided a simple yet sturdy device for arrestingthe downward feeding movement of a cartridge from a lipless magazinevertically mounted in the top of the receiver. Since the device ismounted to the bolt, the extension and retraction thereof can beproperly timed in relation to the actual feeding and chamberingmovements of the cartridge without the necessity for complicated andexpensive cam means in the receiver. Moreover, the actuation of thecartridge retainer is coordinated with the function of the extractor andejector in a simple yet positive manner which is not readily subject tomalfunction. This is extremely important inasmuch as the cartridges arerelatively fragile and cannot be subjected to rough handling orexcessive impact with the operating parts of the firearm.

Although a particular embodiment of the invention has been described indetail herein, it is evident that many variations may be devised withinthe spirit and scope thereof and the following claims are intended toinclude such variations.

I claim:

1. In a firearm having a receiver, a barrel, a bolt s1idably disposed inthe receiver for recoil and counterrecoil movement, and a liplessmagazine vertically mounted in the top of the receiver for dispensingcartridges into the counterrecoil path of the bolt, the improvementcomprising a cartridge holding tray slidably secured to the underside ofthe bolt for movement between a retracted and an extended position,spring means normally urging said tray forwardly into the extendedposition thereof beneath the cartrdge being dispensed from the magazine,said tray being positioned beneath the bolt for contact with the rearend of the barrel during the counterrecoil movement of the bolt wherebysaid tray is forced rearwardly to the retracted position thereof, andmeans for latching said tray in the retracted position until the nextcartridge in the magazine is dispensed therefrom.

2. The combination defined in claim 1 wherein said tray includes aforwardly opening longitudinal slot in the forward end thereof having arearward portion of reduced width forming a pair of shoulders, and saidmeans for latching said tray in the retracted position thereof comprisesan extractor pivotally mounted in the forward end of the bolt to dependtherefrom in vertical alignment with said slot in said tray forengagement with said shoulders therein, said extractor having aforwardly extending claw engageable with the rear end of a cartridge inthe barrel, and an ejector fixedly mounted in the receiver to dependinto the extraction path of a fired cartridge case for imparting pivotalmovement thereto about said extractor claw as a fulcrum whereby saidextractor is simultaneously pivoted out of engagement with saidshoulders to free said'tray for forward movement into the vertical pathof the next cartridge being dispensed from the magazine.

3. In a firearm, a receiver having an upper cartridge feed opening and alower cartridge ejection opening in vertical alignment, a barrel fixedlysecured in the forward end of said receiver, a bolt slidably disposed insaid receiver for reciprocal movement between recoil and counterrecoilpositions, a lipless magazine releasably secured in said cartridge feedopening for successively dispensing rimmed cartridges into longitudinalalignment with the forward path of said bolt to be chambered therebyinto said barrel, an extractor pivotally mounted in an open slot in theunderside of said bolt adjacent the forward end thereof, said extractorhaving a forwardly extending claw engageable with each cartridge duringthe recoil movement of said bolt, a cartridge holding tray slidablymounted to the underside of said bolt for longitudinal movement betweena retracted and an extended position relative thereto, said tray havinga forwardly opening longitudinal slot therein in vertical alignment withsaid extractor, said slot having a rear section of decreased widthforming a pair of shoulders, means on said tray for positioning thefront end thereof for contact with the rear end of said barrel duringthe counterrecoil movement of said bolt whereby said tray is forcedrearwardly to the retracted position thereof, spring means for pivotingsaid extractor to positon the rear end thereof in latching engagementwith said shoulders in said tray, and an ejector fixedly mounted in saidreceiver to depend into the path along which each cartridge case iswithdrawn from said barrel during the recoil movement of said boltwhereby the cartridge case is pivoted about said extractor claw as afulcrum for exit from said cartridge ejection opening, the pivotalmovement of the extracted cartridge case being utilized to impart acorresponding pivotal movement to said extractor which releases saidtray for forward movement to the extended position thereof in thevertical path of the next cartridge being dispensed from the magazine.

4. The combination defined in claim 3 wherein the interior of saidmagazine includes a vertical rib engageable with each cartridge thereinto prevent tilting thereof out of parallel alignment with thelongitudinal axis of said barrel.

5. The combination defined in claim 3 including a fixed post projectingupwardly from said tray into the underside of said bolt, a rod extendingthrough said post and formed with an enlarged head at the rear endthereof, and a spring seated between said head and said post forimparting forward movement to said tray upon the release thereof by saidextractor.

No references cited.

1. IN A FIREARM HAVING A RECEIVER, A BARREL, A BOLT SLIDABLY DISPOSED INTHE RECEIVER FOR RECOIL AND COUNTERRECOIL MOVEMENT, AND A LIPLESSMAGAZINE VERTICALLY MOUNTED IN THE TOP OF THE RECEIVER FOR DISPENSINGCARTRIDGES INTO THE COUNTERRECOIL PATH OF THE BOLT, THE IMPROVEMENTCOMPRISING A CARTRIDGE HOLDING TRAY SLIDABLY SECURED TO THE UNDERSIDE OFTHE BOLT FOR MOVEMENT BETWEEN A RETRACTED AND AN EXTENDED POSITION,SPRING MEANS NORMALLY URGING SAID TRAY FORWARDLY INTO THE EXTENDEDPOSITION THEREOF BENEATH THE CARTRDGE BEING DISPENSED FROM THE MAGAZINE,SAID TRAY BEING POSITIONED BENEATH THE BOLT FOR CONTACT WITH THE REAREND OF THE BARREL DURING THE COUNTERRECOIL MOVEMENT OF THE BOLT WHEREBYSAID TRAY IS FORCED REARWARDLY TO THE RETRACTED POSITION THEREOF, ANDMEANS FOR LATCHING SAID TRAY IN THE RETRACTED POSITION UNTIL THE NEXTCARTRIDGE IN THE MAGAZINE IS DISPENSED THEREFROM.